Boiler furnace



Jan. 8, 1929.

A. RUHR oILER FURNACE Filed Jn. s, 192s 2. shams-sheen a v Patented Jan.8, 1929.

` i Tiara ics.

ARNOLD EHR, OE BERLIN,` GERMANY, AssIGNoE. To INTERNATIONAL COMBUSTIONENGINEERING COREORATION, or NEW YORK, N:="Y., A- CORPORATION oF DELA-WARE.

BOILER EUENACE.

Application led January 5, 1926, Serial No.

This. invention relates to boiler-furnaces, and more especially to thattype of furnace in which the combustion space is very large-ly delinedby boiler tubes subject to radiant heat. the invention beingparticularly useful in connection with stationary ,boiler installationsburning pulverized coal.

It has heretofore been ,proposed in such pulverized Icoal burninginstallations to arrange water screens within 'the combustion chamber,such water walls or screens being composed of a plurality of boilertubes or tubes connected into the circulation of the' boiler. These`have been employed on theside walls; the rear walls; above the ash pit,

and elsewhere.

In accordance with the present invention,

I propose to insure more effective and better circulation through suchelements, while, at'.

means for enforcing circulation.

I accomplish the foregoing, together with such' other objects asmay-hereinafter appear, or are incident to my invention, by means of aconstruction which'I have illustrated in the-preferred form in theaccom- *panyin'g drawings, whereinv Fig. 1 isafragmentaryverticalsection through a boiler-furnace embodying myimprovements, and' Fig. 2 is a transverse vertical sectionv throug'pone-half of the boiler-furnace shown in Figdl. l '7 Referring now tothe drawings, the reference character Afdenotes the combustion@ chamberwhich' has an Outletthroat 7 atl its upper part, the .pulverized`coalbeing :1dmitteddownwardly into the upper part of the combustionchamber through the arch 8 by means of a row of suitable burners 9,v thefuel and flame stream taking a U-shape course through the combustionchamber, with combustion completed'before' the rstpass of the mainboiler B is reached. A portion of the air for combustionis admittedthrough" the burners, and the balance is admitted through rows of airinlets 10 located at successive levels in the front wall 11,"which is jpreferably made hollow, 4so that the combustion air admitted through theinlets 10 is heated in traversing the space within the front wall. lInfront of `the rear wall 12 of the combustion chamber is a water wall j acomposed of comparatively closely spaced tubes 13, the upper endsofwhich are conthe same time, 4dispensing with any lspecial/Al Figa- 2.A pnrV of tubes 18 connect each half 79,279, and in' Germany septembera1, 1925.`

nected into the lower ormud drum 14 of the boiler. These tubes arepreferably small 1in diameter, so as not to weaken the drum struc ture.vPairs'of the tubes 13 are connected 'i at their lower ends intojunctionblocks 15.A

Above the ash pit C- the combustion chamber is the water screen Z), suchscreen being composed of tubes 16 spaced well apart to permit the refuseparticles gravitating out of the .fuel and flame stream to freely passto the ash pit, such particles being thereby cooled below the melting'point in orderthat the refuse'particles .may deposit in the" ash pit inreadilyremovable form.

The upper ends ofthe tubes 16 are con-:53 nected into the4 junctionboxes. 15,-and the' lower endsof the tubes 16 are connected A,into theheader 17, this header being preferably divided 'by a division plate 17ainto two vhalves .as indicated in dot and dash lines in of the header`17 with the mud drum 145, such tubes 18 constituting downcomers andbeing lpreferably somewhat larger in diameter than the tubes 16, whichlatter, in turn, are larger in'diameter than the tubes 13.

By this arrangement the water screen and.

the rear water wall a have local circulation therethrough, although theyareconnected into the main boiler. It will also be seen soI that thewater screen and the-water wall t are divided into two units or groupsof equal number by tubes. This insures a moreuniform arrangement is suchas to .insure rapid and unrestricted circulation through the waterscreen and the water wall, and to insure that the circulation shallaways beupwardly temporarily and even reverses. This is overcome by thedowncomer connections 18 which 'areexterior of the combustion chamber,and Awhich-provide the local circulation hereinbefore referred to..

Coming'now to the screens or water'walls for the sidewalls Of thecombustion chamber, it will be seen that I have divided this intotwounits a?, e, there being preferably two such units, each of which iscomposedof small tubes 19. The tubes of' each unit passoutwardly f orconnection into the headers-2Q, 20,'A

circulation through all of the tubes, and ove1- comes one ofthediiculties heretofore encountered in this art. At the same time,' the atthe top, and2l, 2l, at thebottom. A downcomcr 22 connects each of thelow-er -headers 2l 'to themud, drum lll, and an upcomer 2:3

connects each of the headers 2O to the h xader 24, which, `in turn, isconnected by a multiplicity of small pipes 25 to one of the upper drumsof the boiler, this being done to preventu'ealicning of the drumstructure, and to in securing an equalizingeject. as between the twounits on each side wall ot' the combustion chamber. The pipes compare`in .size with the pipes 18, as do the pipes 23, and the pipes 19 comparein sizewith the pipes 13.

Thus, it will be seen that each unit has its op'n independentcirculation, an( that by splitting the side water walls into theseunits, there is a tendency tosecure more unit'orm circulationtherethrough, this end being` also v.

.t-,ujrthcred by having the pipesI 223 empty `into thc header 2l,asabove set forth. For reasons already Apointed out in Connection withthe other units described, there will always be more eective andconstantly upward How through the units (Z, e, ot each side water wall.These results are further ensured byI the fact that I connect theheaders 20 and 21 by means of tubes 19a of which `there are a pairconnecting each pairo headers, such tubes lying' exterir of the' furnaceand constituting 'downcomers. By virtue of the local circulation thusmade possible, flow through the dou'ncomers 22 is assisted. q

In order to prevent weakening-of the drum structure 14,I prefer to`connect 'the pipes IS and 22to headers 26,which4 in turn, are connectedto the drum l-l by a plurality ot small pipes 2T. y

I claim zl i l. In combination, a boiler having upper drums and a lowermuddrum and interconnecting' tubes, a combustion chamber', a. tubularscreen for an upright -wall thereof, the tubes of which are divided intogroups, upper and lower headers for each zgroup, a douncomer-'from themud drinn to the lower header of each group, an upcomer from the upperheader of-each group, and a downeomer from` .each upper to eachlowerheader, a header common to the downcomers, a plurality ot' smalltubes connec-tmg'said header to the upperand lower headers for eachgroup, a..

downcomer leading,` from theboiler to' the `lower header ot' each group,an upcomerfrom the upper header of each group, a header common to thedowncolners, a plurality ot smallVV tubes connecting. said header to theboiler, a header common to the upcoiners, and

a 'plurality of small tubesconnecting; said header to the boiler.

3. In combination, a boiler having upper steam and water drums and a muddrum, a

'bank ot upcomer tubes connect-ing said` mud drum with a steam and waterdrum. certain' of the tubes being subject to radiant heat, a bank ofdowncomer tubes connecting' a second of the steam and water drums withvthe mud drum, means connecting; the steam and water drums, a combustionchamber h'avingr tubular water 'walls detining'ya substantial portion ofthe combustion space and subject to radiant heat, and means connecting'said water walls into the circulation of the'boiler and arranged so thatthe delivery from tubes ot the installation subject to radiant heat isdivided between the steam and water drums.

et. In combination, a boiler having a pair ot" upper steam and waterdrums, and a lower mud drum and interconnecting tubes, a combustionchamber, boiler tubes :tor an 'upright wall of the combustion chamber,downeomer lmeans from the mudl drum to said boilers tubes,'upcomer meansfrom said boiler tubes' to one of the upper drums, boiler tubes foranother upright wall of the combustion chamber, a bottom screen for thecombustion chamber, downcomer means from the mud drum to said bottomscreen, and means connecting said bottom screen to said last mentionedyboiler tubes, said last mentioned tubes being connected into the muddrum to deliver thereinto. I

In testimony' whereof I have hereunto signed my name.V

ARNOLD mitm.

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